I need to remove 2004 toyota sequoia tailgate door panel to get access the rear tail light to install a backup camera. I don't see any obvious removal points.

Slide the plastic cover off the tailgate ******** the passenger side to reveal a 10mm bolt.

Remove the bolt and the strap/

Using a flat prying instrument, remove the center trim section one the inside of the tailgate above the window.

Grab the top edges of the side trim sections on the inside of the tailgate and pull down to remove.

Using a flat instrument, pry at the bottom edge of the tailgate main trim panel, it is held on with about 12 plastic pop-in fasteners so it will take several 'pops' before it is released.

Behind that there is a metal access cover the width of the tailgate, held on by ~5x pop in fasteners and ~10x 10 mm bolts. Remove the bolts and pop the panel loose, it will hang by the wiring so support it while you do your camera work :)

The license plate trim panel, should you need to remove it, requires remoaval of the license plate.

Then remove ~3x 10mm bolts from the top of the panel, accessed from the inside.

Using long needle nose pliers compress the pop-fasteners holding the lower corners of the license plate trim panel on, being careful not to let it drop and slide down the vehicle, scratching the paint :)